Three lineages of extant algae including amabis biologia volume unico ancestors of land plants vertically evolved from the cells which first acquired plastids. This gave rise to the second-hand or secondary plastid-containing algae, a diverse assemblage including disparate organisms such as euglenoids, dinoflagellates and kelps. Dallas Lueilwitz Country: Bulgaria Language: Such kind of cellular merging, called primary endosymbiosis, likely occurred only once.